Core B, entitled the Tissue Analysis Core, will provide crucial support for this Program Project by analyzing human and mouse tissue for each of the four projects. Core B is an integral part of this Program Project for three reasons. First, each project in this effort relies heavily on tissue analysis to accomplish its goals, both with respect to biological studies as well as in testing the validity off new approaches to molecular therapy. Second, analysis of the tissue and image processing requires specialized reagents and expertise in labor-intensive efforts to produce high quality output in a repetitive manner. Third, with the amount of tissue expected to be analyzed, centralizing tissue analysis of the skin will allow other personnel to pursue individual efforts. The aims of the Core are organized around three types of analysis: 1) tissue morphology and image analysis, 2) RNA expression analysis, and 3) protein analysis. Tissue morphology and image processing of the skin will allow rapid analysis of experimental samples. RNA expression analysis using both radioactive and non-radioactive probes will be used to confirm viral expression and to analyze tissue differentiation markers in. Immunohistochemical analysis of both mouse and human tissues will be used for determining efficacy and durability of gene transfer techniques and analysis of differentiation markers in both human and mouse in. A tissue bank for samples of common interest to the program will continue from the previous funding cycle.